Container vacuum capping method



Nov. 30, 1965 J. B. CORMACK, JR, ETAL 3,220,153

CONTAINER VACUUM CAPPING METHOD Filed July 10, 1961 5 Sheets-Sheet 1INVENTORS JAY/72655 Carma/a, J/I,

Nov. 30, 1965 J. B. coRMAcK, JR., ETAL 3,220,153

CONTAINER VACUUM CAPPING METHOD Filed July 10, 1961 5 Sheets-Sheet 5 #5A 942 w w 6 1965 J. B. CORMACK, JR., ETAL 3,220,153

CONTAINER VACUUM CAPPING METHOD Filed July 10, 1961 5 Sheets-Sheet 5INVENTORS 0w 0,067; 526,072 572 Tfifarezaflci,

United States Patent 3,220,153 CONTAINER VACUUM CAPPING METHOD .larnesB. Cormack, Jan, Oak Park, Donald H. Zipper,

Elmhurst, and Stephen T. Moreland, Chicago, Ill., as-

signors to Continental Can Company, Inc., New York,

N .Y., a corporation of New York Filed July 10, 1961, Ser. No. 122,973 6Claims. (Cl. 5322) The invention relates to new and improved means foruse in container vacuum capping and a new and improved method forobtaining a low oxygen content in a container undergoing vacuumizingbefore capping. More specifically, the invention is directed to a newand improved vacuum capping machine having a special filter and capapplication unit forming a part thereof, the machine being particularlyadapted for capping containers filled with particulate or powderymaterial the retention of which is difficult to control during normalcontainer evacuation and capping operations. With regard to theoperation of the vacuum capping machine including the special containerfilter and cap application unit forming a part thereof, the inventionfurther is specifically directed to a special method of treating thefilled container to obtain a low oxygen content in the same in a new andimproved manner.

There are many different proposed types of vacuum capuing machines someof which are capable of efficient use. Such machines are quitecomplicated with regard to structural and operational aspects and aredifficult to maintain in efiicient operating condition. Furthermore,vacuum sealing machines as known prior to this invention are oftenlimited in use depending on the particular product with which thecontainers are filled. By way of example, powdery particulate material,such as instant coffee and the like, create vacuum packaging dificultiesdue to their tendency to be readily displaced from the container whensubjected to the vacuumization process conditions. Filtering means suchas a cloth or screen have been proposed for positioning over the opentop or mouth of a container during evacuation thereof. However, a lowoxygen content condition must exist at the time the cap or closure isapplied to the container and the attempts to meet this requirement haveled to very complicated, often unworkable, mechanical arrangements. Inthis regard, the fine and powdery material is often drawn against thecap and interferes with the forming of an effective hermetic seal.

A number of the powdery food products, such as instant coffee, are verysensitive to oxygen deterioration at least in certain respects. Withregard to instant coffee, certain aromatic constituents therein arequite sensitive to the residual oxygen remaining in the cappedcontainer. During the filling of containers with particulate materials,it has been the general practice to provide means to establish andmaintain a surrounding nitrogen blanket thus eliminating air from thefilling operation and preventing occlusion thereof throughout the loosemass of coffee particles introduced into the container. While thisprocedure aids materially in improving the keeping qualities of thecoffee product, it nevertheless has been quite difiicult to providesuitable mechanical means whereby the head space of the filled containerand the interstices between the particles of product can be evacuated toan extent that the residual oxygen content therein is quite low. In thisregard it is considered that a residual oxygen content of more than 2%is undesirable.

A specially designed high speed vacuum capping machine particularlyadapted for use in capping containers filled with particulate materialsuch as instant coffee is disclosed and claimed in the copendingapplication Serial No. 122,498 filed July 7, 1961. This machine iscapable of vacuum treating a container filled with particulate orpowdery material to provide for a residual oxygen content of at least aslow as 2% oxygen on the basis of the free volume of the container andcapping containers at a rate of about 300 containers per minute. Thecapping speed and evacuation efiiciency of this machine constitutes amaterial advance in the art as prior to the development of the machine,a residual oxygen content of about 2% could be obtained but not at thespeed of operation desired. The present invention deals with uniquecontainer evacuation and filter unit means forming a part of theaforesaid machine which materially contribute to the efiiciency ofoperation of the same. This invention is further directed to the specialmethod of container evacuation used in the machine to obtain the highspeed low residual oxygen results.

It is an object of the present invention to provide a new and improvedfilter means for use in a vacuum capping machine during evacuation of afilled container and cap application thereto.

Another object is to provide a new and improved vacuum capping machinehaving as a part thereof a special filter and cap application unitadapted for efiicient operation with a container during evacuationthereof and cap application thereto, the filter portion of the unitbeing of a design permitting dual functioning thereof and especiallybeing capable of preventing excessive displacement of particulatematerial from the container during evacuation thereof.

Still another object is to provide a new and improved method of treatinga filled container to obtain a low oxygen content in the same, themethod being particularly adapted for incorporation in a special form ofvacuum capping machine as an operational concept thereof.

Another object is to provide a new and improved meth 0d of treating acontainer filled with powdery-like material to obtain low oxygen contentin the same, this method involving the utilization of a barometric legeffect in the filtered retention of particulate material in thecontainer during evacuation thereof.

Other objects are specifically set forth will become apparent from thefollowing detailed description of the invention made in conjunction withthe accompanying drawings wherein:

FIG. 1 is a partial vertical section of a special vacuum capping machinewith certain parts thereof being illustrated in elevation, this machinemaking use of the new and improved filter and cap application unit andmethod of operation of the present invention;

FIG. 2 is a top plan of the machine as viewed generally along line 2-2in FIG. 1, this view further including legends as to the variousportions of the cycle of operation of the machine;

FIG. 3 is an enlarged fragmentary, partial vertical section of one ofthe vacuum chamber and cap application assemblies of the machine andillustrating the filter and cap application unit of the presentinvention as well as other means adapting the machine for operation inaccordance with the method of the present invention;

FIG. 4 is a vertical section of the valve assembly shown in FIG. 3 takengenerally along line 44 therein;

FIG. 5 is a view similar to FIG. 3 illustrating operational aspects ofthe assembly during operation of the machine;

FIG. 6 is a transverse section of the jar gripping arrangement of theassembly of FIG. 5 taken generally along line 66 therein;

FIG. 7 is a partial view similar to FIG. 5 illustrating additionaloperational aspects of the assembly;

FIG. 8 is a view similar to FIG. 3 illustrating cap application to acontainer; and

-bly 43 positioned thereabove.

FIG. 9 is perspective of one form of filter member of the presentinvention.

The vacuum capping machine of FIGS. 1 and 2 is fully disclosed in theaforementioned copending application and will be briefly describedherein. The machine as best shown in FIG. 1 includes a center upstandingcolumn 10 suitably secured at the bottom thereof to a base member 11.The column 10 is provided with an axially extending passage 12 closedoff at the bottom thereof by a plug 13 and terminating upwardly beyondthe mid-point of the column. The upper end of the passage 12 hasassociated therewith a plurality of radially outwardly directed openings14 extending through the column 10. The upper end of the column 10 isprovided with aseparate axially directed passage 15 which at the upperend thereof is in communication with a conduit 16 suitably attached tothe column '10. The lower end of thepassage 15 communicates with aplurality of radially directed openings 17 extending through the column10. The lower end of the passage 12 is in communication with a conduit18 which is suitably secured to the column 10 and extends radiallyoutwardly therefrom through the base member 11. The passage 12 includingthe conduit 18 provides for the delivery of an inert gas, such asnitrogen, for use in the machine in a manner to be described. Thepassage 15 through its associated conduit 16 is connected to a suitablevacuum source (not shown) for a purpose to be described.

The base member 11 has as a part thereof a drive arrangement including agear housing 20 in which a plurality of gears 21, 22, 23 and 24 aresuitably mounted. The gear 21 is driven through a gear box 25 suitablymounted on the base member 11 and provided with a drive shaft 26extending therefrom for suitable connection to a motor (not shown). Thegear box 25 further includes an upwardly directed driven gear 27 whichis meshed with a large gear 28 fixedly secured to an annular flangemember 3% formed integral with a vertical sleeve portion 31 of acontainer supporting assembly which is generally designated by thenumeral 32.

The container supporting assembly 32 basically includes an annularradially projecting platform portion 33 integrally formed with thesleeve portion 31 and mounting therein through peripherally located,circumferentially spaced groove-like openings 34 a plurality ofcontainer supporting and lifting platform or platen assemblies generallydesignated by the numeral 35. The sleeve portion 31 of the containersupporting assembly 32 is supported on sleeve bearings 36 at its upperand lower ends about the column 10 for rotation thereabout as driven bythe gears 27 and 28. The top surface of the base member 11 has securedthereto an annular cam track 37 the top surface of which operativelyengages a cam roller 38 forming a part of each platen assembly 35. Thetrack 37 functions to control operation of the platen assemblies 35during rotation thereof about the center column 10. In this regard, eachplaten assembly 35 includes a container supporting and lifting platen 40on which a container 41 is positioned, the left-hand platen 40 as viewedin FIG. 1 having been raised by the cam track 37 to place the container41 supported thereon in a bell-shaped chamber 42 of a vacuum chamber andcap application assem- The right-hand platen 40 as viewed in FIG. 1 isin its lowermost position as controlled by the associated portion of thecam track 37 and the container 41 supported thereon is free from thechamber 42 of the assembly 43 positioned thereabove.

Mounted above the container supporting assembly 32 is a containerevacuation and capping assembly generally designated by the numeral 44.This assembly includes a housing 45 mounted on the center column 10 forrotation thereabout in synchronized relation with the containersupporting assembly 32. The housing 45 defines a large annular vacuumchamber 46 with which the passage 15 of the column 10 is incommunication through the openings 17. The chamber 46 has mountedtherein a plurality of circumferentially spaced, radially directedstrengthening fins 47 which also function as baffie plates incooperation with the relatively large size of the chamber to dampenpulsation of air drawn through the chamber 46 during operation of themachine. Below the chamber 46, the housing 45 is formed with a secondsmaller annular chamber 48 having therein an apertured annular insert 50and circumferentially spaced strengthening fin baflies '51. The insert50 provides communication with the openings 14 of the passage 12 of thecolumn 10 for a supply of inert gas during operation of the machine. Thelower end of the housing 45 has depending therefrom a plurality ofcircumferentially spaced, fixed drive pins 52 the lower ends of whichare clamped in looking collars 53 mounted in the radial plate 33 of thecontainer supporting assembly 32. Each locking collar 53 is providedwitha locking rod 54 which may be operated externally of the machine toloosen or tighten the collarv during vertical adjustment of the upperassemblies as will be described. By means of the drive pins 52, theupper assembly 44 is rotatably driven by the lower assembly 32 to thusmake use of a single power source in operating the machine. Furthermore,the provision of the plurality of vertically adjust-able means includingthe pins 52 eliminates lost motion between the-interconnectedassemblies.

The container evacuation and capping assembly 44 further includes aradially directed annular plate member 55 provided with a plurality ofcircumferentially spaced openings therein adjacent the outer peripherythereof in which the vacuum chamber and cap application assemblies 43are removably mounted. Each of these assemblies generally includes thebell-shaped container receiving chamber 42, a valve assembly 56, a capdelivery assembly 57 (see FIG. 2), and an upwardly projecting camactuated operating portion 58. The operating portion 58 is controlled bya cam roller 60. The valve assembly 56 is operated by a plurality of camrollers 61. The cap delivery device'57 is operated by a pair of camrollers 62.. The valve assembly 56 is suitably connected to thevacuumization chamber 46 by a pipe 63 and is suitably connected to theinert gas supply chamber 48 through a pipe 64. A suitable cap deliverychute is positioned relative to the machine as indicated by the brokenlines identified by the numerals 65. Caps are delivered by this chute toeach cap delivery device 57 when the same is withdrawn outwardly fromits associated chamber 42 as shown in the right-hand portion of FIG. 1.The left-hand.

portion of FIG. 1 illustrates a cap delivery device 57 engaged with itsassociated chamber 42 during container evacuation and cap applicationoperation of the machine.

The machine further includes a cam actuating assembly generallydesignated by the numeral 66. This assembly includes an internally.threaded vertical adjustment sleeve 67 received about the upper end ofthe column-10 and supporting a vertically slidable, non-rotatable,spline connected sleeve portion 68 on the column. Annular thrustbearings 70 are mounted at the lower end of the sleeve 67 in supportingengagement with portions of the sleeve 68. The upper end of the housing45 of the container evacuation and cap application assembly 44 is atleast partially supported on the sleeve 68 through a rotatable bearingstructure 71. The top portion of the sleeve 67 is provided with a collar72 to which a suitable lever or wrench bar 73 may be attached to raiseor lower the sleeve 67.

The cam actuating assembly 66 further includes a radially directedannular plate 74 which has mounted thereon about the outer peripherythereof a cam track member 75 in which the cam rollers 66 of the vacuumchamber and cap application assemblies 43 are received. The cam track 75opens outwardly of the machine thus permitting ready withdrawal of thecam rollers 60 therefrom. The assembly 66 further includes a dependingsleeve-like cam track portion 76 which on the outer surface thereof isprovided with a plurality of circumferentially variable ca-m tracksengaging the cam rollers 61 and 62 of the vacuum chamber and capapplication assemblies 43.

The particular arrangement described regarding the positioning and typeof cam tracks used in the machine provides for efficiency in machineoperation and maintenance. The cam actuation assembly 66 is fixedagainst rotation on the center column and the cam track portion 76thereof extends downwardly between the chamber assemblies 43 and thecenter column to permit ready removal of any assembly 43 for maintenanceor replacement purposes. In other words, the chamber assemblies 43 maybe individually removed from the machine without disturbing any otheroperating mechanism or part of the machine and the arrangement is suchthat replacement of a chamber assembly 43 on the machine results inautomatic alignment of the various cam actuated parts thereof with thecam track portions of the assembly 66. Furthermore, regardless of fromwhat portion of the cycle a chamber assembly is removed, replacement ofthe same or a new assembly in the same portion results in immediateadjustment of the assembly to conform to the particular portion of thecycle.

The container evacuation and capping assembly 44 is verticallyadjustable with the cam actuating assembly 66 along the center column10. The assembly 44 is, in effect, rotatably supported on the sleeve 68through the rotatable bearing means 71. Of course, this assembly isfurther supported by the container supporting assembly 32 through thedrive pin arrangement including the pins 52 and locking collars 53. Theinterconnected assemblies 44 and 66 may be adjusted vertically relativeto the container supporting assembly 32 by threaded movement of thesleeve member 67 of the assembly 66 along the upper threaded end of thecolumn 10. All other column engaging parts will slide therealong uponloosening of the drive pin arrangement. A change in vertical positioningof the upper assemblies will be necessary when the ma chine is used withcontainers of less than maximum height. During vertical adjustment ofthe interconnected assemblies 44 and 66, the interengaging operationalparts thereof will maintain their cooperative positions. Thus no specialadjustments are necessary other than a raising and lowering of theinterconnected assemblies.

FIGS. 1 and 2 further show that to one side of the machine and arrangedtangentially relative thereto is an endless conveyor 77 carried on asuitable frame 78 (FIG. 1) and adapted to deliver containers to and fromthe vacuum capping machine. A container guide plate assembly 80 issuitably mounted over the conveyor 77 and projects over an adjacentportion of the plate 33 of the container supporting assembly 32. Theguide plate assembly is provided with a container delivery slot portion81 and a container removal slot portion 82. The conveyor 77 and guideplate assembly 80 constitute a portion of a container feed and take-offdevice which among its elements includes a container position controlmeans 83 rotatably mounted on a shaft 84 connected to the gear 23. Thecontrol means is in the form of a pair of cooperating disclike membersas best shown in FIG. 1. The control means includes at least one pocketportion 85 in which a container is received from the conveyor 77 anddelivered onto a platen 46 of the plate 33. Each pocket portion 85 isspecially designed to provide for the introduction of a container ontothe container supporting assembly 32 at a velocity equal to therotational speed of the supporting assembly and further providing forpositive holding of the container on a platen 40 until at least the topof the container is received in a capping chamber 42.

A synchronizing container feed control means in the form of a rotatingdisc-like member 86 is mounted on a shaft 87 operated by the gear 24.This member is provided with at least one container receiving pocketportion 88 and operates to positively separate each container deliveredthereto on the conveyor 77 for proper feeding thereof to the containerposition control means 83. The container feed and take-off device iscompleted with the provision of a container helper member 90 whichprojects into the slot portion 82 of the guide plate assembly 80. Thehelper member 90 rotates on a shaft 91 driven by a gear member mountedin the drive arrangement housing 20. The helper member is provided withat least one concave edge portion 92 designed to engage a container andmove the same from a platen 40 of the container supporting assembly 32onto the conveyor 77 following capping of the container.

With the general arrangement of the machine having been described, FIG.2 illustrates the operational portions of a complete cycle of operationinvolving 360 rotation. Capless containers 41 are delivered by theconveyor 77 into the slot portion 81 of the guide plate assembly. Thesynchronizing feeding member 86 provides for controlled delivery of thecontainers to the container position control means 83 whichautomatically places each container on a lowered platen 40 carried bythe container supporting assembly 32. As the container movescounterclockwise in the machine as viewed in FIG. 2, the platensupporting the same is raised by the cam track 37 and eventually the topof the container is at least partially received in a chamber 42 of anoverhead vacuum chamber and cap application assembly 43. The positioncontrol means 83 maintains engagement with the container until theoverhead chamber receives at least a portion thereof thus preventingspilling or crushing of the container during high speed operation of themachine.

The cycle of the operation continues through the sec ond quadrant duringwhich the chamber 42 is evacuated with the container confined within andinert gas is used to sweep the same. Upon passing through the thirdquadrant, the container still confined in a chamber 42 is supplied witha cap which is automatically twisted thereon in complete sealingengagement. Additional operations occur in the third quadrant of thecycle as indicated by the legends on FIG. 2 and these particularoperations will be subsequently referred to. Upon entering the fourthquadrant, the vacuum established in the chamber 42 containing the cappedcontainer therein is released and the platen 40 supporting the containeris lowered in time for the container to be received in the slot portion82 of the guide assembly 80. The container is then ultimately engaged bythe helper member 90 which provides for positive movement of thecontainer onto the conveyor 77 by means of which it is taken away fromthe machine. As indicated in FIG. 2, the empty platen as it passesthrough the guide plate assembly 80 after having a capped containerremoved therefrom and prior to receiving an uncapped container thereonmay be subjected to automatic cleaning to remove any product that mightaccumulate thereon. Any suitable means may be utilized to provide acleaning action in the cleaning zone such as an air jet.

Each vacuum chamber and cap application assembly 43 as shown in FIG. 3includes a special filter unit 93 positioned in the top portion of thechamber 42. The filter unit 93 is suitably mounted on the bottom end ofa vertically directed shaft 94 which constitutes a part of the operatingassembly 58 previously described. Vertical reciprocal operation of theshaft 94 and the attached filter unit 93 is controlled by the cam roller60 in engagement with the cam track 75 of the cam actuating assembly 66.As will be described in detail, the shaft 94 is cam operated to raiseand lower the filter unit 93 several times during a complete cycle ofoperation of the machine to first provide for container evacuation andthen provide for container cap application. With regard to container capapplication, the shaft 94 has suitably received thereon a pulley-typewheel 95 a projecting portion of which is shown in FIGS. 1 and 2. Thiswheel is mounted within the operating portion 58 including the shaft 94and is designed to permit reciprocal movement of the shaft 94 throughthe center of the same and yet impart rotation to the shaft 94 and theattached filter unit 93 when the pulley wheel is rotated. In this regardthe type of cap applied to the container 41 by the machine is arotatable cap which includes a fiat top panel portion formed with adepending skirt portion along the inner surface of which lockinglug-type means are provided for engagement with outer surface threadedportions of the neck of a container. The cap is also provided with asealing gasket on the inner face thereof. A cap 96 is shown in FIG. 3 ascarried by the cap delivery device 57. Rotation of the shaft 94 andfilter unit 93 to provide for the twisting of a cap 96 onto a container41 is brought about by a friction shoe assembly 97 fixedly mounted onthe radial plate 74 of the cam actuating assembly 66 as shown in FIGS. 1and 2. The shoe assembly 97 extends downwardly over the cam track 75 andis located at a point on the machine which corresponds to the capapplication portion of the cycle of operation as shown in FIG. 2. Thusas the upper assembly 44 rotates relative to the cam actuating assembly66, the pulley wheels 95 of successive assemblies 43 will be engaged bythe fixed shoe assembly 97 and the shaft 94 and attached filter unit 93will be rotated through a prescribed arc for cap application to acontainer.

Referring particularly to FIG. 3, the filter unit 93 is mounted againstrotation on the bottom end of the shaft 94 and includes a rigid porousfilter member 98 of inverted cup-like shape fixedly mounted between acollar member 100 suitably attached to the shaft 94 and a magnet holder101. The filter member 98 as best shown in FIG. 9 is formed with anannular side Wall portion 102 of substantial height, a generally flattop wall portion 103 and a bottom edge radially outwardly directedflange 104. The top wall portion 103 is provided centrally thereof witha fiat sided aperture 105 which engages a similarly shaped portionforming a part of the filter mounting means including the collar 100 andmagnet holder 101. The fiat sided aperture 105 fixes the filter member98 to the mounting means therefor to provide for positive rotation ofthe filter member 98 upon rotation of the shaft 94. The filter member 98may be formed from any suitable adequately rigid material whichestablishes a plurality of rigidly defined pores throughout the entirefilter member with the pores being smaller than the particle size of thematerial in a container 41. The.

erally L-shape in cross section. The gasket 106 is fixedly mounted in aninner circumferential groove of a collar 107 which is received about thefilter member 98. The upper end of the collar 107 is provided with aninwardly directed flange portion which retains therein a spring member108 in abutment with the upper surface of the flange portion 104 of thefilter member 98. The magnet holder 101 has projecting from the bottomportion thereof a permanent magnet 110 which is designed to magneticallyhold a cap 96 in the gasket 106 as shown in FIG. 8.

The arrangement described provides for unused cap rejection by thefilter unit 93 in the event that a cap is not accepted by a container 41or if the supply :of containers is interrupted and a chamber 42 does notreceive a container therein. The top inner portion of the chamber 42includes an annular shoulder 111 arranged for abutment with the topsurface of the collar 107 upon extreme upward movement of the shaft 94and filter unit 93. Im-

mediately following vacuum release in the portionof the cycle shown inFIG..2, the overhead cam track operates to raise the shaft 94 and filterunit 93 to a height exceeding its height at any other time during thecycle of operation. This special raising results in abutment bewteen theupper end of the collar 107 with the shoulder 111 and the spring 108 iscompressed permitting separation between the gasket 106 and the bottomsurface of the filter member 98. During this operation the magnet israised well above the gasket 106 and its attraction to an unused capheld by the gasket 106 is eliminated with the result that the unused capwill fall downwardly out of the chamber 42 onto an exposed portion ofthe machine from which it can be removed.

FIG. 3 adequately illustrates the details of the valve assembly 56 whichis attached to each chamber 42. The valve assembly includes a valvehousing suitably detachably mounted on a chamber 42 in association withan open side manifold portion 112 of the chamber. The valve assemblyhousing includes three valve chambers 113, 114 and 115. The outer endsof the chambers define valve seats in the manifold area. Poppet valves116,

117 and 1111 close off the valve chambers and are operatedv on rodswhich carry at their opposite ends the cam rollers 61 previouslydescribed in FIG. 1. Any suitable spring arrangement (not shown) may beused in maintaining the valves in chamber sealing engagement with theirrespective seats. FIG. 4 illustrates the valve housing 56 as including apassage 120 extending from the chamber 113 into communication with thepipe 64 through which inert gas is supplied. The chamber 114 is incommunication with an atmospheric vent 121 and the chamber 115communicates through a passage 12?. with the pipe 63 through which avacuum is drawn.

The bottom open end of each chamber 42 is defined by a containergripping assembly 123 which is grooved along the bottom edge thereof andseats a platen engaging gasket 124. The assembly 123 is formed with acircumferentially continuous slot 125 in which a resilient containergripping member 126 is mounted. This member has a base portion ofgenerally outwardly opening channel-like shape which is locatedoutwardly of the slot 125'. The gripping member is dimensioned to definespaces 127 between the same and the outer surfaces above and below theslot 125 for movement toward the surfaces into container grippingrelation during operation of the machine. The channel-shaped baseportion of the gripping member 126 isreceived in a chamber 128 formedbetween the top and bottom chamber defining members of assembly 123 andwhich is in communication with atmospheric pressure through a pluralityof openings 130 therein. The outer surface of the base portion isidentified by the numeral 131 and is of substantial area for responsiveaction to atmospheric or other suitable pressure. The portion of thegripping member 126 which projects through the slot 125 is formed with aplurality of circumferentially spaced rib-like members 132. Theprojecting faces of these mem-' bers are designed to engage the outersurface of a container. Upon evacuation of the chamber 42 followingbottom sealing thereof by a platen 40, atmospheric pressure will act onthe outer surface 131 of the gripping member 126 and the same willcontract and fill the spaces 127 during movement of the projections 132into tight container gripping engagement as shown in FIG. 6. In thismanner the container 41 is held against rotation during that portionofthe cycle of operation in which the cap is twisted onto the container.

Each vacuum chamber and cap application assembly 43 includes a capdelivery device 57 as previously described. FIG. 3 illustrates thisdevice as including a sleeve-like housing 133 which at one end is openand seats a continuous gasket 134 thereabout, the other end of thehousing being closed and journaling therethrough a rod 135. The rod atits inner end mounts a cap supporting boss 136cm which a cap 96 may bedeposited as shown in FIG. 3 The housing 133 is slidable along the rod135 toward and away from the chamber 42 by means of supporting rods 137only one of which is shown, these rods being suitably reciprocallyjournaled in a portion of the chamber 42 with the rod 137 illustratedextending inwardly beyond the chamber 42 and carrying thereon one of thecam rollers 62 previously described. The outer end of the rod 135 isfixedly secured through a link 138 to an operating rod 140 which is alsosuitably journaled for reciprocating movement in a portion of thechamber 42 not shown, the rod 140 projecting inwardly beyond the chamber42 and carrying thereon the other cam roller 62 previously described.

The chamber 42 includes in an outer side portion thereof a cap deliveryopening 141 which is dimensioned to receive therethrough the boss 136and a cap 96 mounted thereon. The open end of the sleeve housing 133 andthe gasket 134 are dimensioned to completely surround the cap deliveryopening 141 and seal the same. By reason of the operating rods 137 and140 being controlled by cam track portions carried on the dependingsleeve 76 of the cam actuating assembly 66, the boss 136 may be movedinto and out of the chamber 42 and the sleeve housing 133 may be movedinto and out of sealed engagement with the opening 141 as well as intoand out of enclosing relation with the boss 136.

FIG. 3 illustrates the positions of the various operative elements of asingle evacuation and capping station at the time that a filledcontainer 41 is placed on a supporting platen 40 below a chamber 42.This occurs during movement of the station through the loading zone asdesignated in FIG. 2. As shown in FIGS. 1, 2 and 3, by reason of camactuation, the sleeve housing 133 of the cap delivery device 57 is fullyretracted on the rod 135 to expose the cap supporting boss 136 and a cap96 is deposited thereon from the chute 65. The station then movesthrough the portion of the cycle during which the platform or platen 41)is raised lifting the container 41 into the chamber 42 to the extentillustrated in FIG. 5. The platen 41 engages the chamber bottom sealinggasket 124 and the cap delivery sleeve housing 133 is cam actuated intosealing engagement with the chamber 42 about the cap delivery opening141. In this portion of the cycle the cap supporting boss 136 ispositioned within the sleeve housing 133 out of the chamber 42.

During the vacuumization and inert gas sweeping portions of the cycle asshown in FIG. 2, the filter unit 93 is lowered into engagement with theopen top surface or mouth of the container 41. FIG. 5 illustrates theengagement of the top edge of the container by the gasket 106. Thepoppet valve 118 is opened by cam actuation and the chamber isevacuated. The container 41 is evacuated through the filter member 98the outer surface portions of which are at least substantially exposedfor efficient evacuation. During evacuation of the chamber 42,atmospheric pressure acting on the outer large face area 131 of thecontainer gripping member 126 results in inward projection of the ribs132 into engagement with the outer surface of the container as shown inFIG. 6. Thus with a differential pressure condition the ribs will engagethe container and hold the same against rotation Within the chamber 42.The circumferential spacing of the ribs 132 provides for pressureequalization above and below the container gripping member 126 withinthe chamber 42 and the establishment of a vacuum condition below thecontainer gripping member 126 aids in maintaining a tight seal betweenthe platen 40 and the chamber gasket 124.

Following adequate evacuation of the chamber 42 and container 41, thevacuum control poppet valve 118 is closed as a result of cam actuationand the poppet valve 116 is opened as shown in FIG. 7. With the openingof this valve a supply of inert gas is placed in communication with thechamber 42 and this gas fills the chamber and passes in reverse flowthrough the filter member 98 into the head space of the container. Thisoperational step is preferred in that the reverse flow through thefilter member tends to keep the same clean and redeposit any particulatematerial collected thereon back into the container. Furthermore, as willbe described in detail, the improved method of operation of a vacuumcapping ma chine forming a part of this invention involves thecombination of at least several steps of vacuumization and inert gasfeed back. The details of the method of operation as well as a preferredconcept thereof will be described in detail.

Following inert gas injection, the inert gas valve 116 is closed and thevacuum control valve 118 is reopened to reduce the pressure in thechamber 42 and remove the inert gas therefrom. Still further, subsequentcontrolled feed back of inert gas will preferably be relied upon forpurposes of reducing the vacuum established in the container to permitready removal of a cap from a container by the user thereof.

FIG. 8 illustrates the portion of the cycle in which the cap 96 istwisted onto the container 41 in hermetically sealed relation. Followingcompletion of the vacuumization and inert gas injection cycles, the rod135 of the cap delivery device 57 is cam actuated to move the capsupporting boss 136 thereof through the cap delivery opening 141 intothe interior of the chamber 42. During this operation the filter unit 93is retracted upwardly by the shaft 94. Thus the boss 136 injects the cap96 between the filter unit 93 and the open top of the container 41.Prescribed vacuum conditions are maintained during this operation.

The filter unit 93 is then lowered to place the gasket 106 thereof intoengagement with the cap 96 and the magnet 110 engages the cap to providefor lifting thereof with the filter unit 93 when the same is againretracted upwardly into the chamber 42. The boss 136 is then withdrawnfrom the chamber 42 back into the sleeve housing 133. The filter unitwith the cap 96 carried thereby is then moved downwardly in the chamber42 to place the cap on the top of the evacuated container 41 as shown inFIG. 8. The shaft 94 is rotated in the manner previously described andthe cap 96 is tightly applied to the container in hermetic sealingrelation.

Proper hermetic sealing requires the embedding of the top edge of thecontainer 41 in the gasket material carried in the cap 96. Thus thedownward pressure of the filter unit 93 must be rather substantial. Inorder to prevent the reaction force from separating the platen 40 fromthe bottom gasket 124 of the chamber 42, a special outer cam roller 142forms a part of each platen assembly 35 as shown in FIG. 1. The camroller 142 is fixedly mounted to rigid portions of the platen assemblyand at the cap application portion of the cycle of operation, the roller142 engages a cam track segment 143 mounted on the outer surface of thecam track 37. This momentary rigid contact between the roller 142 andthe cam track segment 143 provides a solid base for the platen assemblyadequate to overcome any cap application reaction force.

Referring again to FIG. 8, following completion of the cap applicationportion of the cycle, the poppet valve 117 is opened by cam actuation asindicated in broken lines and the chamber 42 is vented to theatmosphere. In this manner the vacuum within the chamber is broken andthe container gripping member 126 retracts to its original position topermit ready withdrawal of the container from the chamber. Furthermore,the sleeve housing 133 of the cap delivery device 57 is free to moveaway from the chamber 42 and back along the rod 135 to completely exposethe boss 136 as in FIGS. 1 and 2 to permit delivery of another capthereto to start the cycle again. The filter unit 93 is moved upwardlyin the chamber 42 and the platen 40 is lowered to withdraw the containerfrom the chamber. The platen 4t readily separates from the chamber 42 byreason of the vacuum having been broken therein.

As set forth above, the filter member 98 may be formed from any suitablerigid porous material capable of providing the requisite porosity andstrength for use in the manner described. The filter member may beformed from sintered metallic particles such as beads or the like havingan average particle size of from 26 to 51 microns. The metal used may bebrass and the beads are suitably charged in a mold which is heated to atemperature of approximately 1680 P. where a hydrogen atmosphere is usedand 1620 P. where a nitrogen atmosphere is used. At such temperaturesthe. accumulated mass of beads in the mold cavity combine in thewell-known manner to form a sintered article which is uniformly porousthroughout.

The filter member may also be formed from sintered nylon powder or othersuitable materials. Ultrafine nylon powder on the order of 1 to 3microns is compacted in a mold at about to 50 tons per square inchpressure and sintered at about 450 F. Sintering is carried out in anon-oxidizing atmosphere such as inert gas, vacuum, or under oil. Afilter of this type may have the same shape as described above and thepore walls thereof are sufficiently rigid to prevent product particleentrapment.

Regardless of the manner in which the filter member 98 ismade, the shapethereof is such that a barometric leg effect is provided. Thisconstitutes an important aspect of the present invention in that, aspreviously described, powdery materials are rather diflicult to handleduring evacuation of a container filled with the same. The provision ofthe side wall portion 102 of the filter member 98 with an adequateheight provides a substantial amount of space confined by the filtermember in communication with the head space of the container. Thus theevacuation procedure is substantially completed before the particulatematerial can rise well above the container. For eflicient high speedoperation of the capping machine it is essential that the vacuumconditions be established virtually instantaneously and the immediatesubjection of a strong vacuum on particulate material tends to lift thesame. The barometric leg defined by the filter member preferably rangesfrom about 1 /2 to 3 /2 inches in height. A height of 3 inches has beenfound quite satisfactory in a capping machine of the type describedoperating at a rate of approximately 300 containers per minute. Thebarometric leg provides an area in which the granular or powderymaterials may expand upwardly resulting in separation of the particlesby means of which air may be readily withdrawn at a maximum velocityfrom the container. Furthermore, this particular arrangement making useof the type of filter member disclosed provides for the use of maximumpossible filter area. This rigid porous filter member not only proivdesmeans by which cap application pressure may be transmitted to the capand container, but also provides greater pore wall strength. in that anyproduct particles impinging against the filter will readily falltherefrom as they cannot expand the rigid pore walls of the filter andthus become stuck or trapped therein. In this regard the rigid porousfilter member constitutes a substantial improvement over the use ofconventional silk filters or screens.

The method of treating the interior of a container to obtain low oxygencontent therein will be described in conjunction with the establishmentof vacuum conditions expresssed in inches of mercury vacuum. Theexpressing of vacuum conditions in these terms is fully accepted andwidely practiced in the art. Atmospheric pressure will normally readbetween 29 and 30 inches of mercury. It is in this range of 29 to 30inches of mercury between atmoshperic pressure and absolute zeropressure the container capping industry works. ditions existing betweenatmospheric pressure and absolute zero pressure are expresssed in inchesof mercury vacuum. In this regard if the atmospheric pressure isapproximately 30 inches of mercury and a vacuum is Thus the vacuum con-7 drawn in a container to an extent of 10 inches of, mercury vacuum, theresulting absolute pressure in the container would be 20 inches. This ismerely the difference in pressure within the container, and the existingatmospheric pressure. Mechanical capping machines are conventionallysupplied with gauges which provide readings in terms of inches ofmercury vacuum.

With regard to high speed capping operations, it has been found that avacuum of 26 /2 inches can be quickly established (approximately 0.2second) in a container. Drawing a vacuum to 28 /2 inches is quitedifficult and requires a substantially longer period oftime because theair molecules remaining are widely dispersed. As previously described,with many oxygen sensitive food prod-.

ucts the container should preferably be evacuated to an extent thatresidual oxygen is not substantially greater than 2%. This would requirethe establishment of a vacuum on the order of at 1east28 inches. Thetime required to do this in accordance with vacuum capping machineoperational methods practiced prior to this invention is prohibitiveinsofar as the maintaining of high speed capping operations isconcerned.

In order to obtain the desired minimum residual oxygen in a container,it has been found that by the use of a series of evacuationsinterspersed with inert gas feed back, the desired residual oxygencontent can be established while maintaining high capping speedoperation. Specifically, the vacuumization cycle comprises subjectingthe vacuum chamber to vacuumization conditions to establish therein avacuum of at least about 25 inches of mercury vaccum. This vacuum isthen reduced by the injection of an inert gas, such as nitrogen, todecrease the vacuum to no less than 10 inches of mercury vacuum. Thefeed back of nitrogen to the vacuum chamber causes a diffusion of theair within the chamber. air, mixing with the feed back nitrogen thusprovides a new gas mixture with a low percent oxygen. Subsequentvacuumization therefore becomes more efiective with regard to percent ofoxygen relative to standard air. In this regard the barometric legportion of the filter member contributes substantially as it provides anincreased nitrogen fill area to assure good mixing of the residual airand oxygen. The next step in the cycle involves the re-establishing ofthe original vacuum conditions, namely, evacuating to at least about 25inches of mercury vacuum. In this step the nitrogen mixed with theresidual air is removed from the container and a material reduction inresidual oxygen content occurs.

Preferably, the first evacuation step will be carried out undervacuumization conditions which will result in the establishment of26 /2inches of mercury vacuum in the container. A vacuum source of about 29inches is adequate for this purpose. The container vacuum willpreferably be reduced only to about 15 inches of, mercury vacuum by feedback of nitrogen. The original 26 /2 inches of mercury vacuum will thenbe re-established for the purpose described above. Again, preferably the26%. inches of vacuum will be subsequently reduced to no less than 10inches of vacuum, or about 15 inches of vacuum, by re-introduction ofnitrogen. This last step 7 results in reducing the capping vacuum andpermitting easier removal of the cap from the container by the user ofthe product. Obviously, the subsequent re-filling with nitrogen will notdisturb the desired residual oxygen content originally established.

The method described does not interfere with high speed cappingoperations. As previously set forth, a vacuum of 26 /2 inches can beestablished in the head space of a container virtually instantaneously(approximately 0.2 second). While this initial vacuumization is notadequate to reduce the residual oxygen content to the extent desired,the subsequent re-fillin'g with nitrogen followed by evacuation again tore-establish the initial 26 /2 inches of vacuum assures a reduction inresidual oxygen content -to the desired level. Each step may be accom-The residual plished in a fraction of a second and thus the combinationof steps does not hinder high speed capping operations. The sequence ofsteps may be repeated to any extent desired. This method when used inconnection with products which are not immediately oxygen sensitive canbe effective to completely eliminate existing practices requiringcontainer filling under nitrogen blanket conditions. Elimination of thishighly controlled step can be quite important with regard to savings incost and reduction in product packaging time and equipment.

Obviously certain modifications and variations of the invention ashereinbefore set forth may be made without departing from the spirit andscope thereof, and therefore only such limitations should be imposed asare indicated in the appended claims.

We claim:

1. In a method of vacuum capping containers having a loose powdery-likematerial packed therein, the steps of covering the mouth of thecontainer with a rigid caplike filter member which provides asubstantial area above the mouth of the container for expansion of theproduct when subject to vacuum for withdrawal of air through the mouthof the container, the filter being of a fineness sufficient to preventexcessive displacement of the powdery-like material from the container,forming a vacuum chamber about the filter covered mouth of thecontainer, evacuating the chamber to withdraw air from the containerthrough the filter, feeding into the chamber an inert gas so as to passthe gas in reverse flow through the filter into the head space, againvacuumizing the chamber to remove substantially all of the inert gas,lifting the filter above the mouth of the container when the chamber isevacuated and positioning a closure cap between the open bottom of thefilter and the open top of the container, lowering the filter and caponto the top of the container and using the filter member as anapplicator in applying the cap to the mouth of the evacuated containerin hermetic sealing relation thereon.

2. In a method of vacuum capping containers having a loose powdery-likematerial packed therein, the steps of covering the mouth of thecontainer with a rigid caplike porous filter member which provides adownwardly opening chamber of substantial depth above the mouth of thecontainer for expansion of the product when subject to vacuum forwithdrawal of air out of the container through the filter, the filterpores being of a size relative to the material particle size to preventpassage of the powdery-like material, forming a vacuum chamber about thefilter covered mouth of the container, evacuating the chamber towithdraw air from the container through the porous filter member,feeding into the chamber an inert gas so as to pass the gas in reverseflow through the pores of the filter member into the head space in themouth of the container, again vacuumizing the chamber to remove theinert gas, lifting the filter member above the mouth of the containerafter the chamber is evacuated, positioning a closure cap between theopen bottom of the filter member and the open mouth of the evacuatedcontainer, lowering the filter member and the cap onto the top of thecontainer and using the filter member as an applicator in applying thecap to the evacuated container in hermetic sealing relation.

3. In a method of vacuum capping containers having a loose powdery-likematerial packed therein, the steps of covering the mouth of thecontainer with a porous filter member having a downwardly openingcup-like shape providing an area of substantial depth above the mouth ofthe container for expansion of the product when subject to vacuum forwithdrawal of air through the mouth of the container and the filtermember, the filter member having pores smaller than the size of theparticles of the powdery-like material so as to prevent passage of thepowdery-like material through the filter 14' member, forming a vacuumchamber about the covered mouth of the container, evacuating the chamberto withdraw air from the container, feeding into the chamber an inertgas so as to pass the gas in reverse flow through the pores of thefilter member into the head space within the mouth of the container,vacuumizing the chamber to remove substantially all of the inert gas,raising the filter member above the mouth of the container when 'thechamber is again evacuated, seating a closure cap on the open bottom ofthe filter member above the open top of the container, lowering thefilter member and cap onto the top of the container and using the filtermember as an applicator in applying the cap to the evacuated containerin hermetic sealing relation.

4. A method of treating a container filled with powdery-like material toobtain low oxygen content in the same, said method comprising coveringthe mouth of the container with an inverted cup-shaped filter memberwhich defines a barometric leg of from about 1 /2 to 3 inches in heightso as to provide a substantial area above the head space in which thematerial may expand upwardly, evacuating the container through thefilter member with the evacuation being carried out to an extent toestablish at least about 25 inches of mercury vacuum, reducing thevacuum to no less than 10 inches of mercury vacuum by introducingtherein an inert gas, again evacuating the container through the filterto about 25 inches of mercury vacuum, again reducing the vacuum to noless than 10 inches of mercury vacuum by introducing therein an inertgas, and hermetically capping the container.

5. A method of treating a container filled with powdery-like material toobtain low oxygen content in the same, said method comprising coveringthe mouth of the container with an inverted cup-shaped filter memberwhich defines a barometric leg of from about 1 /2 to 3 inches in heightso as to provide a substantial area above the head space in which thematerial may expand upwardly, evacuating the container through thefilter member With the evacuation being carried out to an extent toestablish 26 /2 inches of mercury vacuum, reducing the vacuum to about15 inches of mercury vacuum by introducin therein an inert gas, againevacuating the container through the filter to about 25 inches ofmercury vacuum, again reducing the vacuum to about 15 inches of mercuryvacuum by introducing therein an inert gas, and hermetically capping thecontainer.

6. In a method of vacuum capping containers having a loose powdery-likematerial packed therein, the steps of covering the mouth of thecontainer with a porous filter member having a downwardly openingcup-like shape providing an area of substantial depth above the mouth ofthe container for expansion of the product when subject to vacuum forwithdrawal of air through the mouth of the container and the filtermember, the filter member having pores smaller than the size of theparticles of the powdery-like material so as to prevent passage of thepowdery-like material through the filter member, forming a vacuumchamber about the covered mouth of the container, evacuating the chamberto an extent sufiicient to establish at least about 25 inches of mercuryvacuum, introducing into the chamber an inert gas so as to reduce thevacuum to no less than 10 inches of mercury vacuum with the gas passingin reverse flow through the pores of the filter member into the headspace within the mouth of the container, again evacuating the chamber toabout 25 inches of mercury vacuum, introducing an inert gas into thechamber to again reduce the vacuum to no less than 10 inches of mercuryvacuum, raising the filter member above the mouth of the container,seating a closure cap on the open bottom of the filter member above theopen top of the container, lowering the filter member onto the top ofthe container and 15 16 applying the cap to the container in hermeticsealing rela- 2,534,254 12/ 1950 Felber -L 53-22 mm 2,583,866 1/1952Mero 53-87 2,610,779 9/1952 Fouse 53-87 References Cited by the Examiner3,039,882 6/1962 Chnton et a1. 99152 X UNITED sTATEs PATENTS 5 I FOREIGNPATENTS 2,149,790 3/1939 Roesch 53-22 458,131 7/1949 Canada- 2,335,19211/ 1943 Moore 99152 FRANK E. BAILEY, Primary Examiner. 2,426,555 8/1947Jacobs et a1. 53-22 ROBERT A. LEIGHEY, TRAVIS S. McGEHE-E,

2,496,877 2/1950 Krueger r r 5322 X 10 Examiners.

4. A METHOD OF TREATING A CONTAINER FILLED WITH POWDERY-LIKE MATERIAL TOOBTAIN LOW OXYGEN CONTENT IN THE SAME, SAID METHOD COMPRISING COVERINGTHE MOUTH OF THE CONTAINER WITH AN INVERTED CUP-SHAPED FILTER MEMBERWHICH DEFINES A BAROMETRIC LEG OF FROM ABOUT 11/2 TO 3 INCHES IN HEIGHTSO AS TO PROVIDE A SUBSTANTIAL AREA ABOVE THE HEAD SPACE IN WHICH THEMATERIAL MAY EXPAND UPWARDLY, EVACUATING THE CONTAINER THROUGH THEFILTER MEMBER WITH THE EVACUATION BEING CARRIED OUT TO AN EXTENT TOESTABLISH AT LEAST ABOUT 25 INCHES OF MERCURY VACUUM, REDUCING THEVACUUM TO NO LESS THAN 10 INCHES OF MERCURY VACUUM BY INTRODUCINGTHEREIN AN INERT GAS, AGAIN EVACUATING THE CONTAINER THROUGH THE FILTERTO ABOUT 25 INCHES OF MERCURY VACUUM, AGAIN REDUCING THE VACCUUM TO NOLESS THAN 10 INCHES OF MERCURY VACUUM BY INTRODUCING THEREIN AN INERTGAS, AND HERMETICALLY CAPPING THE CONTAINER.